Last of IPv4 addresses assigned as focus turns to IPv6

The last IPv4 addresses have been allocated, highlighting the need for companies and organizations to move to a new system amid the ever increasing number of net-connected devices. The Internet Assigned Numbers Authority (IANA) made the announcement at an event in Miami on Thursday.

Each of the five regional Internet registries has been allocated a single block of around 16 million addresses. While true exhaustion would be hard to gauge -- a small number of IP addresses will be held for several years for the transition -- the rate at which the different registrars will burn through their allocations will likely vary.

APNIC, the registrar in the Asia-Pacific region, will likely run out first in the next few months. ARIN (North America's registrar) and RIPE NCC (controlling Europe, Middle Eastern, and Russian IP needs) are in a better position, likely being able to make it through the year on their current allocation.

In developing nations such as Africa and Latin America (AfriNIC and LACNIC respectively), the much slower uptake of connected devices could mean their allocations of IPv4 addresses last for possibly several years. Either way, officials with IANA stress it is time to start thinking about IPv6.

Whereas IPv4 only had 4.3 billion addresses due to its 12-digit structure, IPv6's 39-digit structure dramatically increases the number of available addresses and makes exhaustion practically impossible for the foreseeable future.

"No one was caught off guard by this," ICANN president and CEO Rod Beckstrom said in a statement. "Adoption of IPv6 is now of paramount importance, since it will allow the Internet to continue its amazing growth and foster the global innovation we've all come to expect."

Many ISPs and companies have already been working for quite some time on IPv6 implementation, so this milestone will likely go unnoticed for quite awhile. However, inaction is not a possibility -- every connected device needs an IP address to communicate, and without moving to IPv6 address sharing must occur.

While in some cases this would work in theory, it may cause headaches for the routing of IP-to-IP traffic (VoIP, etc.). This makes that option only a temporary fix at best.